l. In the
distance, to the south-west, erosion seemed to have taken place on a
great scale in the side of the table-land.

The highest point we had so far reached on the plateau on which we were
travelling since leaving the Araguaya was 2,400 ft. There again we found
another of the extensive grassy _cuvettes_--the flat bottom of which was
only 30 ft. lower than the highest point of the plateau. A luxuriant
growth of _burity_ palms and _birero_ trees adorned the centre, the
latter very tall and handsome, with smooth white bark and only a dense
tuft of dark green foliage at their tops. In the _cuvettes_ I saw, the
growth of the tall vegetation invariably ran the long way of the oval.

The sky that evening showed great streaks of transparent lines of mist
from west to east, the central radiation of these being formed of lines
so precisely parallel that they seemed to have been drawn with rule and
dividers. Directly overhead those lines gradually blended into a more
indefinite mass. The radiations did not begin from the vanishing sun on
the horizon, nor at the point diametrically opposite on the east, but
began to appear only one-tenth up the entire circle of the sky, both west
and east.

Almost globular cloudlets, with the lower section cut off in a horizontal
plane--quite typical, as we have seen, of the cloud formation on that
Central Brazilian plateau--crowded the sky, quite low to the north, and
also a great many small ball-like clouds which showed with some
brilliancy against the blue sky.

The sunsets in Central Brazil were to me always a source of intense joy,
interest, and admiration. With certain characteristics which repeated
themselves frequently, they always displayed wonderful effects of light
and a most peculiar formation of clouds.

Before reaching camp we passed another oval _cuvette_ with a longitudinal
row of trees--so green and tidy as to be just like a portion of a
well-kept English park (elev. 2,350 ft.). Another bit of wonderful
scenery, with immense prismatic rocky mountains--really more like
dykes--appeared in the distance; and also a vertical walled mountain in
the foreground.

CHAPTER XXI

A Beautiful Lagoon--Strange Lunar Display--Waves of Lava--Curious
Grottoes--Rock Carvings--A Beautiful Waterfall

WE camped at the Lagoa Formosa--or "Beautiful Lagoon"--a large, verdant,
oval-shaped lagoon, entirely covered with grass, only 140 ft. lower than
the top of the plateau (e